Conventionally, as an antenna for a car navigation device installed in a vehicle and a PND (Personal Navigation Device) attached to a vehicle, a rod antenna attached outside a vehicle or a film antenna that can be bonded to the windshield or the rear glass is used frequently.
In the case where a moving object, such as a vehicle, receives a broadcast, due to the influence of fading, the signal level of the received signal varies considerably, and therefore, diversity reception is performed frequently for the purpose of making up the deterioration in the received signal due to the influence of fading. However, in order to perform diversity reception, it is necessary to provide a plurality of antennas.
Because of this, as an antenna for performing diversity reception, the film antenna that hardly affects the external appearance is selected more frequently than the rod antenna that mars the external appearance because the number of antennas increases.
For example, in Patent Literature 1, the technique to enable stable reception of the broadcast wave by installing a film antenna on four surfaces, i.e. the front, rear, left, and right surfaces of a vehicle.